Conventionally, there is widely known an electronic device having a base such as a printed wiring board and a circuit chip mounted on the base. This type of electronic device is used to control an electronic apparatus by being disposed within this electronic apparatus, or is used independently to exchange information with an external device. As an example of such an electronic device, there is known a RFID (Radio_Frequency_IDentification) tag that exchanges information with an external device represented by a reader/writer in a non-contact manner using radio waves. There are various types of RFID tags. As one type of RFID tag, there is proposed a tag having a structure in which a conductor pattern for radio communications and an IC chip are mounted on a base made of a plastic, a piece of paper, etc (see, for example, Japanese Laid-open Patent Publication No. 2001-156110). It has been conceived to use this type of RFID tag in such a manner that the RFID tag is adhered to an article to identify the article by exchanging information about the article with an external device.
FIG. 1 is a schematic cross-sectional diagram of an example of a conventional RFID tag.
A RFID tag 90 illustrated in FIG. 1 includes: a base 91 made of a flexible PET film or the like; an antenna 92 made of a conductor pattern and formed on the base 91; and a circuit chip 93 disposed on the antenna 92. In this circuit chip 93, a circuit for exchanging information with an external device through the antenna 92 is incorporated. The circuit chip 93 has connecting terminals 93a formed under the circuit chip 93, which are electrically connected to the antenna 92 by soldering or the like. Further, the circuit chip 93 is secured onto the base 91 with an adhesive 94. On the base 91 of the RFID tag 90, there are also provided: a potting compound 95 covering the circuit chip 93; and a ring-shaped reinforcing member 96 disposed to surround the circuit chip 93. There is also provided a covering member 97 that covers the entire tag main body including the base 91, the antenna 92, the circuit chip 93, the potting compound 95 and the reinforcing member 96. The potting compound 95 includes an inner portion 95a filling the inside of the reinforcing member 96 shaped like a ring. The inner portion 95a covers the top of the circuit chip 93 and seals the circuit chip 93 on the base 91.
There are cases where the RFID tag 90 receives a strong external force when the RFID tag 90 is used by being attached to an article made of a flexible material, such as clothing. However, since the RFID tag 90 is provided with the potting compound 95 and the reinforcing member 96 disposed around the circuit chip 93 to protect the circuit chip 93, a crack in the circuit chip 93 per se is prevented even when a pressure is applied to the RFID tag 90 in the thickness direction of the base 91.